Buggy code:
public class DispatcherServletTests extends TestCase { private static final String URL_KNOWN_ONLY_PARENT = "//knownOnlyToParent.do" ; private MockServletConfig servletConfig ; private DispatcherServlet simpleDispatcherServlet ; private DispatcherServlet complexDispatcherServlet ; @ Override protected void setUp ( ) throws ServletException { } private ServletContext getServletContext ( ) { } public void testDispatcherServletGetServletNameDoesNotFailWithoutConfig ( ) { } public void testConfiguredDispatcherServlets ( ) { } public void testInvalidRequest ( ) throws Exception { } public void testRequestHandledEvent ( ) throws Exception { } public void testPublishEventsOff ( ) throws Exception { } public void testFormRequest ( ) throws Exception { } public void testParameterizableViewController ( ) throws Exception { } public void testHandlerInterceptorSuppressesView ( ) throws Exception { } public void testLocaleRequest ( ) throws Exception { } public void testUnknownRequest ( ) throws Exception { } public void testAnotherFormRequest ( ) throws Exception { } public void testAnotherLocaleRequest ( ) throws Exception { } public void testExistingMultipartRequest ( ) throws Exception { } public void testMultipartResolutionFailed ( ) throws Exception { } public void testHandlerInterceptorAbort ( ) throws Exception { } public void testModelAndViewDefiningException ( ) throws Exception { } public void testSimpleMappingExceptionResolverWithSpecificHandler1 ( ) throws Exception { } public void testSimpleMappingExceptionResolverWithSpecificHandler2 ( ) throws Exception { } public void testSimpleMappingExceptionResolverWithAllHandlers1 ( ) throws Exception { } public void testSimpleMappingExceptionResolverWithAllHandlers2 ( ) throws Exception { } public void testSimpleMappingExceptionResolverWithDefaultErrorView ( ) throws Exception { } public void testLocaleChangeInterceptor1 ( ) throws Exception { } public void testLocaleChangeInterceptor2 ( ) throws Exception { } public void testThemeChangeInterceptor1 ( ) throws Exception { } public void testThemeChangeInterceptor2 ( ) throws Exception { } public void testNotAuthorized ( ) throws Exception { } public void testHeadMethodWithExplicitHandling ( ) throws Exception { } public void testHeadMethodWithNoBodyResponse ( ) throws Exception { } public void testNotDetectAllHandlerMappings ( ) throws IOException , ServletException { } public void testHandlerNotMappedWithAutodetect ( ) throws IOException , ServletException { } public void testDetectHandlerMappingFromParent ( ) throws IOException , ServletException { } public void testDetectAllHandlerAdapters ( ) throws IOException , ServletException { } public void testNotDetectAllHandlerAdapters ( ) throws IOException , ServletException { } public void testNotDetectAllHandlerExceptionResolvers ( ) throws IOException , ServletException { } public void testNotDetectAllViewResolvers ( ) throws IOException , ServletException { } public void testCleanupAfterIncludeWithRemove ( ) throws IOException , ServletException { } public void testCleanupAfterIncludeWithRestore ( ) throws IOException , ServletException { } public void testNoCleanupAfterInclude ( ) throws IOException , ServletException { } public void testServletHandlerAdapter ( ) throws Exception { } public void testWebApplicationContextLookup ( ) { } public void testWithNoView ( ) throws Exception { } public void testWithNoViewNested ( ) throws Exception { } public void testWithNoViewAndSamePath ( ) throws Exception { } public void testDispatcherServletRefresh ( ) throws ServletException { } public void testDispatcherServletContextRefresh ( ) throws ServletException { } public void testEnvironmentOperations ( ) { DispatcherServlet servlet = new DispatcherServlet ( ) ; <START_BUG> ConfigurableWebEnvironment defaultEnv = servlet . getEnvironment ( ) ; <END_BUG> assertThat ( defaultEnv , notNullValue ( ) ) ; ConfigurableEnvironment env1 = new StandardServletEnvironment ( ) ; servlet . setEnvironment ( env1 ) ; assertThat ( servlet . getEnvironment ( ) , sameInstance ( env1 ) ) ; try { servlet . setEnvironment ( new DummyEnvironment ( ) ) ; fail ( "expected<seq2seq4repair_space>IllegalArgumentException<seq2seq4repair_space>for<seq2seq4repair_space>non-configurable<seq2seq4repair_space>Environment" ) ; } catch ( IllegalArgumentException ex ) { } class CustomServletEnvironment extends StandardServletEnvironment { } @ SuppressWarnings ( "serial" ) DispatcherServlet custom = new DispatcherServlet ( ) { @ Override protected ConfigurableWebEnvironment createEnvironment ( ) { return new CustomServletEnvironment ( ) ; } } ; assertThat ( custom . getEnvironment ( ) , instanceOf ( CustomServletEnvironment . class ) ) ; } public void testAllowedOptionsIncludesPatchMethod ( ) throws Exception { } public static class ControllerFromParent implements Controller { @ Override public ModelAndView handleRequest ( HttpServletRequest request , HttpServletResponse response ) throws Exception { } } }

Fix:
ConfigurableEnvironment defaultEnv = servlet . getEnvironment ( ) ;